Well, it turned out I needed to download the demo again (this time from Steam) because the installer I got the first time installed a corrupted version, I guess. Anyway, having finally gotten around to playing it today I can confirm that it is a lot of fun. The combat is fundamentally the same as in DA:O, but feels a lot more fluid and is a lot more interesting to watch. Little tweaks like stunned characters not just standing, swaying on the spot (they now stagger around a little too), closing attacks (the Rogue, for example, will roll or vault along the last couple of metres to the enemy in order to launch an attack), and more interesting animations add a bit of spice to the combat.
I'm less sure on the conversations at the moment. I have a slight concern over the voice acting, but the thing I noticed most was the responses are assigned a symbol to display the kind of attitude they convey. Some of them are obvious (the deep blue "good/virtuous" and the purple jester mask), but others I was a bit unsure of what I'd be about to say. I'd guess those would be explained in the manual for the full game though.
Oh, and the blood's still there, if you were worried. I'll probably be turning the persistant gore off in the full game, I still think conversations after a battle look a little ridiculous with everyone calmly discussing the next step with bits of darkspawn flesh in their hair.